Portable desk



FIG. 1 is a left front perspective view of a first embodiment of a portable desk embodying my new design.

FIG. 2 is a rear elevational view thereof.

FIG. 3 is a front elevational view thereof.

FIG. 4 is a top plan view thereof.

FIG. 5 is a bottom plan view thereof.

FIG. 6 is a left side elevational view thereof, which is a mirror image of the right side elevational view thereof.

FIG. 7 is a left front perspective view of a second embodiment of a portable desk embodying my new design; and,

FIG. 8 is a left front perspective view of a third embodiment of a portable desk embodying my new design. 

The ornamental design for a portable desk, as shown and described. 